Conventionally, a method of managing moving images recorded on a storage medium by using representative images has been proposed. Japanese Patent No. 03081304 discloses using representative images in general moving/still image reproduction apparatus, and especially discloses using representative images for simplified display upon selection of still or moving image. Further, Japanese Published Unexamined Patent Application Nos. Hei 11-176137 and 2000-322875 disclose assigning a representative image to a moving image section, and selecting a section as a target of reproduction designation by using the representative image.
As such representative image is generally used, variety of usage of representative image increases. For example, image management using the representative images can be applied to an editing apparatus as well as the above-described reproduction apparatus.
However, even regarding the same section in a moving image, a representative image appropriate to a user interface upon reproduction and a representative image appropriate to a user interface upon editing are different from each other. Accordingly, if the same representative image is to be used in various apparatuses including an editing apparatus, the following problem occurs.
For example, in FIG. 1, reference numeral 11 denotes a moving image. In this moving image 11, in a section (a), the motion of a batter who holds a bat at the ready and hits a ball is recorded. Numerals 12 and 13 denote representative images regarding the same section (a). The representative image 12, generated from a head frame of the section (a), is an image of the batter at the ready. The representative image 13, generated from a middle frame of the section, which is an image of the batter when he hits the ball. The representative image 13 can be a most appropriate representative image to indicate the content of the section (a).
Generally, one representative image is assigned to one section and is registered. Accordingly, one of the representative images 12 and 13 is actually registered as a representative image of the section (a). The registered representative image can be used as an index image for e.g. a reproduction apparatus. However, if the representative image 13 is registered, upon selection of representative image in the reproduction apparatus, reproduction starts from a status prior to the hit (the reproduction starts from the head of the section (a)), thus a user feels unnatural. On the other hand, if the representative image 12 is registered, when the image is used in an editing apparatus, it is inconvenient that the content of the section (a) cannot be precisely grasped by the image 12. That is, in the example of FIG. 1, it cannot be determined from the representative image 12 whether the section (a) indicates a scene where the batter hits the ball or a scene where the batter swings at the ball and miss. In this manner, an appropriate representative image in one section of moving image depends on the purpose of apparatus to be used.
Conventionally, assignment and management of representative images are necessary in accordance with purpose and usage of moving image data such as reproduction and editing. Accordingly, information on the representative images are redundantly held by purpose such as editing or reproduction, by moving image or still image, or by apparatus or usage. Further, program code for processing to utilize the information on the representative images must be respectively held for the representative images. That is, when the representative images are used in various moving image data processing, the information on the representative images are respectively managed by apparatus or program. Accordingly, it is wasteful to have plural apparatuses and programs for management, and it is further wasteful to independently store the representative image data. To maintain operability in moving image data processing upon use of representative image, management of representative images becomes complicated.